关于iostream中clear函数的疑惑

#include <iostream>

using namespace std;

int main()
{
    int ival;

    while (cin >> ival, !cin.eof())
    {
        if (cin.bad())
        {
        //    throw runtime_error("IO stream corrupted");
        }
        if (cin.fail())
        {
            cerr << "bad data, try again" << endl;
            cin.clear(istream::failbit);
            continue;
        }
        cout << ival << "\t";
    }

    return 0;